Back check and controller for artificial legs



A. FOR STER.

BACK CHECK AND CONTROLLER FOR ARTIFICIAL LEGS.

APPLICATION FILED Auc.1. 192:.

1,415,329. V Patented May 9,1922.

IN VENTOR ETA? ADAM FORSTER, OF.PITTSBURGH, PENNSYLVANIA, ASS IGNOR OF ONE-HALF TO JAMES J. MOUNT, OF PITTSBURGH, PENNSYLVANIA.

BACK CHECK AND CONTROLLER FOR ARTTFICIAL LEGS.

specification of Letters Patent.

Patented May 9, 1922.

Application filed August 1, I921. Serial no. 488,995.

To all whom it may concern:

Be it known that I, ADAM Fonsrnn, acitizen of the United States, and resident of Pittsbur h, in the county of Allegheny and State ofiennsylvania, have invented a new and useful Improvement in BackChecks and Controllers for Artificial Legs; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to a back-check and controller for an artificial limb.

One of the objects of my invention is to provide a device that can be readily adjusted to any make of an artificial limb, the method of securing the same in position being of such a simple character that no difficulty is encountered even by the cripple in fastening or releasing it.

Another object of my invention is to enable the wearer of an artificial leg for an amputation above the knee-joint to walk more naturally and easily, and prevent the leg from dragging in the act of coming forward when stepping.

To these ends my invention comprises the novel feature hereinafter set forth and claimed.

In the accompanying drawing Fig. 1 is a side elevation of a limbcomp'osed of'the thigh-section and leg-section partly broken away and showing my improved back-check and controller applied thereto; Fig. 2 is a rear view; and Fig. 3 is a perspective view of the back-check and controller.

In the drawing the numeral 2 designates the thigh-section and 3 the leg-section which are pivotally connected by the bolt 4 in the customary manner so as to give the proper flexibility at the knee-joint.

The back-check and controller may be made of any suitable metal, or of wood if desired.

Mounted on the hollow-pin 6 in the upper end of the back-check 5 is the double sheave 7 adapted to rotate freely on said pin. At

the lower part of the back-check 5 mounted on the pin 8 is a second double sheave 9. If desired single sheaves may be used, but I prefer to use the double sheaves to enable me to use two continuous cords or straps 10 and 11.

The back-check 5 has the plate 12 which is adapted to bear against the rear of the legsection of the interior thereof, and a cushion or pad 13 is provided against which said movement of the leg-section.

plate bears. The back-check o with the extension 14.

The back-check 5 is pivoted independently of the leg and thigh-sections, and for this purpose a pivotal-pin 15 passes through the hollow-pin 6, and said pivotal-pin is supported by the thigh-section in the rear of the pivotal-bolt 4.

On the interior of the leg-section and extending across same is the stop-pin 16 against which the extension H is adapted to bear and move in bringing the leg back to straight or normal position. The extension 14- carries at its lower end the pad 17 which acts as a cushion when the back-check swings back and strikes the calf-portion of the leg-section.

is provided The cords or straps 10 and 11 pass up and are connected to the suspenders that pass over the shoulders of the 'wearer.

When the leg is in straight or normal position the plate 12 bears against the pad 13 in the rear of the leg-section and acts to prevent any further backward movement of the thigh-section as well as any'forward movement of the leg-section beyond the normal amount. When the limb is bent at the knee the plate 12 moves away from the pad 13, and the back-check is lowered, and as said back-check is mounted on its own pivot back of the knee-bolt 4 it is free to swing back and forth as a pendulum independently of any movement of said sections. Accordingly, when the thigh-section is bent and a pull is made on the straps the leg is brought into straight or normal position by the forward There is an upward pull on the back-check and the legsection is moved forward until the plate 12 is brought into engagement with the pad 13 which checks further movement.

By my invention, I provide a back-check back-check independentlysuspended from i the thigh-section and extending down into .the leg-section adapted to bear against the rear of the leg-section, and a suspender loop engaging the said back-check and adapted to pass over and to be supported on the shoulder of the wearer.

2. The combination of a thigh-section, a leg-section pivotally connected thereto, a back-cheek suspended from said thigh-section in the rear of the pivotal connection between the said leg-section and thigh-section and'extending down into the said leg-section and adapted to bear against the rear thereof, and a suspender loop engaging the said back-check and adapted to pass over and to be supported on the shoulder of the wearer. 3. The combination of a thigh-section and a ieg-seotion pivotally connected together, a baekcheck suspended from the said thighsection extending down into the leg-section and adapted to bear against the rear of the said leg-section, sheaves carried by the said back-check, and a suspender 100p passing around said sheaves and adapted to pass over and to be supported on the shoulder of the wearer.

41. The combination of a thigh-section and leg-section pivotally connected together a back-check suspended from the said thighsection extending down into the said legsection and adapted to bear against the'rear oi the said leg-section, a suspender loop engaging the said back-check and adapted to pass over and to be supported on the sh0u1- ders of the wearer, an extension on said back-cheek, and a stop or abutment inside said leg-section in the path of movement of said extension.

In testimony whereof, I the said ADAM F onsrnn have hereunto. set my hand.

ADAM FORSTER.

Witnesses EDITH K. FREEsE, J OHN F. WILL. 

